The present invention relates to a system for providing fluid to the exterior surface of a vehicle, such as a windshield, for the purpose of cleaning same.
Windshield washer systems have been used in automotive vehicles for many years. As is well known, such systems typically apply a fluid which aids the action of the wiper blades in cleaning the windshield or other exterior surface, such as a lamp lens. Because many vehicles are required to operate in ambient temperatures below freezing, it has been necessary to provide an additive to the fluid so as to depress its freezing point. Typically, methanol is used to depress the freezing point of windshield washer fluid. However, as vehicle emissions regulations become increasingly more stringent, it has become increasingly more desirable to limit the emissions of all forms of hydrocarbons from the vehicle. Accordingly, it is desirable to limit and, in this case, eliminate the use of methanol. Of course, at ambient temperatures below freezing, it is difficult to use neat water. The present invention solves the problems associated with using neat water and allows the cleaning of a windshield with neat water or perhaps with water having a small amount of soap therein, but in either case without the use of methanol.
A windshield washer system for an automotive vehicle includes a fluid reservoir, a pump mounted within the fluid reservoir and a heater mounted in proximity to the pump so as to provide heat to fluid contained within the reservoir. The system further includes a nozzle operatively associated with the pump for applying fluid from the reservoir to an outside surface of an automotive vehicle. The heater may comprise an electric resistance element, such as a positive temperature coefficient element mounted about a pumping chamber of the pump. In any event, the heater provides sufficient heat to the fluid contained within the reservoir to prevent water in the fluid from freezing at ambient temperatures normally encountered by automobiles.
According to another aspect of the present invention, a nozzle incorporated in the present system may be of the telescoping variety such that it has a first position for spraying and a second, or retracted, position when it is not spraying. In this fashion, a neat, uncluttered appearance may be achieved, while protecting the nozzle from damage. In any event, the nozzle is close-coupled to the pump, so as to minimize the fluid volume between the pump and nozzle. This promotes drainback of fluid from the nozzle to the pump, while allowing heat to flow from the pump to the nozzle, thereby further inhibiting freezing of water within the nozzle.
It is an advantage of the present system that separated fluid lines and nozzles are eliminated, with the entire system being contained in a single assembly, so as to allow the protection of the fluid and the entire system from freezing with a single heat source.
It is a further advantage of the present system that the use of hydrocarbon-based freezing point depressants may be eliminated with the present system.
It is another advantage of the present system that the nozzle included with the system is self-draining so as to allow the nozzle to purge itself of fluid when the system is not being energized and therefore to further protect the system against freezing.